# Networking >  OSL MODEL seven layer

## Geek_Guest

*Question asked by visitor sarika phulwade* 

I have a question tell me what is OSL MODEL seven layer? tell me ecah and every layer function and how does it work?

----------


## Haitalk

Basically OSI model divides all functions of a network communication system into 7 layers so that each layer defines standards for each section of the communication system. Please go throught the following links for details..
www.pcsupportadvisor.com/nasample/t04124.pdf
http://www.javvin.com/osimodel.html

----------


## saranyamahendran

hai,
   It is OSI layer(open system interconnection model).
  the seven layers are
application layer-to allow access to network resource
presentation layer-to translate,encrypt and compress data
session layer-to establish,manage and terminate session.
transport layer-to provide reliable end-to-end message delivery and error recovery.
network layer-to move packets from source to destination to provide interworking.
datalink layer-to organize bits into frames,to provide node-to-node delivery.
physical layer-to transmit bits over a medium,to rpovide mechanical and electrical specifications

----------


## sutnarcha

I strongly agree with saranyamahendran. Good answer man.

A new model of OSI has just 5 layers. :EEK!:  
*Physical
DataLink
Network
Transport
Application*

*Session* and *Presentation* layer activities are reduced and are added to *Transport* layer and *Application* layer respectively. :Cool:

----------


## saranyamahendran

yes mam, 
i too agree with u.
but in case of OSI layer we have 7 layers. 
what u have mentioned is TCP/IP suite in which the application ,prsentation and session layer is combined to application layer.
so in TCP/IP suite we have application,transport,network,datalink and physical layer.
and in OSI layer we have
application,presentation,seesion,transport,network,datalink and physical layer..

if there is any change in this layers pls do inform me..

by
saranya

----------


## MotoRooter

The OSI model divides the tasks involved with moving information between networked computers into seven smaller, more manageable task groups. A task or group of tasks is then assigned to each of the seven OSI layers. Each layer is reasonably self-contained so that the tasks assigned to each layer can be implemented independently. This enables the solutions offered by one layer to be updated without adversely affecting the other layers. The following list details the seven layers of the Open System Interconnection (OSI) reference model:

Layer 7Application

Layer 6Presentation

Layer 5Session

Layer 4Transport

Layer 3Network

Layer 2Data link

Layer 1Physical

----------


## rristevski

I remember the layer with this simple idea.....*A*ll *P*eople *S*eem *T*o *N*eed *D*irty *P*ictures

----------


## Sushma Mosali

hi,

Please go through the following attachment and let me know if you have further queries

Thanks
Sushma

----------


## dinesh_boora

> *Question asked by visitor sarika phulwade* 
> 
> I have a question tell me what is OSL MODEL seven layer? tell me ecah and every layer function and how does it work?


Physical layer: Provides electrical, functional, and procedural characteristics to activate, maintain, and deactivate physical links that transparently send the bit stream; only recognizes individual bits, not characters or multicharacter frames. 

Data link layer: Provides functional and procedural means to transfer data between network entities and (possibly) correct transmission error; provides for activation, maintenance, and deactivation of data link connections, grouping of bits into characters and message frames, character and frame synchronization, error control, media access control, and flow control. 

Network layer: Provides independence from data transfer technology and relaying and routing considerations; masks peculiarities of data transfer medium from higher layers and provides switching and routing functions to establish, maintain, and terminate network layer connections and transfer data between users. 

Transport Layer: Provides transparent transfer of data between systems, relieving upper layers from concern with providing reliable and cost effective data transfer; provides end-to-end control and information interchange with quality of service needed by the application program; first true end-to-end layer. 

Session layer: Provides mechanisms for organizing and structuring dialogues between application processes; mechanisms allow for two-way simultaneous or two-way alternate operation, establishment of major and minor synchronization points, and techniques for structuring data exchanges. 

Presentation layer: Provides independence to application processes from differences in data representation that is, in syntax; syntax selection and conversion provided by allowing the user to select a "presentation context" with conversion between alternative contexts. 

Application layer: Concerned with the requirements of application. All application processes use the service elements provided by the application layer. The elements include library routines which perform inter-process communication, provide common procedures for constructing application protocols and for accessing the services provided by servers which reside on the network

----------


## dinesh_boora

Physical layer: Provides electrical, functional, and procedural characteristics to activate, maintain, and deactivate physical links that transparently send the bit stream; only recognizes individual bits, not characters or multicharacter frames. 

Data link layer: Provides functional and procedural means to transfer data between network entities and (possibly) correct transmission error; provides for activation, maintenance, and deactivation of data link connections, grouping of bits into characters and message frames, character and frame synchronization, error control, media access control, and flow control. 

Network layer: Provides independence from data transfer technology and relaying and routing considerations; masks peculiarities of data transfer medium from higher layers and provides switching and routing functions to establish, maintain, and terminate network layer connections and transfer data between users. 

Transport Layer: Provides transparent transfer of data between systems, relieving upper layers from concern with providing reliable and cost effective data transfer; provides end-to-end control and information interchange with quality of service needed by the application program; first true end-to-end layer. 

Session layer: Provides mechanisms for organizing and structuring dialogues between application processes; mechanisms allow for two-way simultaneous or two-way alternate operation, establishment of major and minor synchronization points, and techniques for structuring data exchanges. 

Presentation layer: Provides independence to application processes from differences in data representation that is, in syntax; syntax selection and conversion provided by allowing the user to select a "presentation context" with conversion between alternative contexts. 

Application layer: Concerned with the requirements of application. All application processes use the service elements provided by the application layer. The elements include library routines which perform inter-process communication, provide common procedures for constructing application protocols and for accessing the services provided by servers which reside on the network

----------

